Tangent Arc Query

Going step by step, as per the instruction, for the most efficient way of producing this sketch, I'm not having any joy with this part. I draw a line. I then select the 'tangent arc' command, click the tangent and the line, but my result is not the same as the tutorial, even though I've added the 'tangent' constraint. What am I missing?

If you are still seeing this after trying the suggestions above, try to continue with the example. Sometimes adding additional dimensions/constraints, later on, will still give you the correct final profile. Some of the images in the training are grabbed at the end of modeling the designs.

You will notice that the training screenshot sketch is fully defined (the lines are all black) while your sketch seems to be undefined in some areas (blue lines). Perhaps you might have missed a dimension or constraint in previous steps?